PURPOSE: To manufacture a semi-processed electrical steel sheet having small iron loss and high magnetic flux density by descaling and cold rolling a hot rolled steel sheet contg. specified percentages of C, Si, Mn, P and S and by annealing the cold rolled steel sheet so as to reduce the amt. of C to a specified value or below.

CONSTITUTION: A hot rolled steel sheet consisting of 0.006W0.030% C, 0.1W1.0% Si, 0.75W1.5% Mn, ≤0.150% P, ≤0.005% S and the balance Fe with inevitable impurities or further contg. 0.1W0.3% sol. Al or <0.1% sol. Al and B satisfying B/N=0.1W1.5% is descaled and cold rolled. The steel sheet may be annealed at 650W850°C for ≥30sec before or after the descaling. The cold rolled steel sheet is annealed so as to reduce the amt. of C to ≤0.005%. Thus, a semi- processed electrical steel sheet having small iron loss and high magnetic flux density is obtd.